The invention relates to a turbine set with a turbine which is traversed by water and which is coupled with a generator feeding a constant frequency power distribution network. Such turbine sets are employed to utilize water power for energy generation in particular in river power plants and are known from the literature reference "Bulletin des Schweizer Elektrotechnischen Vereins," 1978, pages 943 to 947.
A distinction is here made between tube turbine sets, where the turbine has a horizontal or slanting shaft, and sets in which the turbine has a vertical shaft. Tube turbine sets were originally designed with a propeller turbine that had fixed blades with the rotor of a generator arranged directly on the outer rim of the runner of the propeller turbine. Such a mechanically simple and sturdily built propeller turbine has the disadvantage, however, that because of the non-adjustability of the blades and because of the constant speed of rotation caused by the generator, the efficiencies at partial load are very poor.
Later, axial flow turbines called Kaplan turbines were developed. These have adjustable runner blades and predominantly vertical shafts and are used in river power plants. A generator lying outside the flow space, and also having a vertical shaft, is connected to the turbine. Also, in tube turbine sets Kaplan turbines with adjustable runners are used in which the generator is located inside a flow body and is driven directly by the shaft of the Kaplan turbine. At this flow body lies inside the water inflow to the turbine, the space available for the generator is limited, which may limit the power output of such generators. For this reason, the use of an outer rim generator has also been provided for a tube turbine set with a Kaplan turbine, with the magnet wheel rim of the generator being mounted on the outer rim of the Kaplan turbine in a hydrostatically separate manner. Such an arrangement is very expensive.